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Saint John’s wort is a medicinal plant that can help treat depression, improve brain function, kill bacteria, and more. Read below to learn more about its health benefits.


Saint John’s wort (Hypericum perforatum) is a plant with yellow flowers whose medicinal uses were first recorded in ancient Greece. The flowering tops of St. John’s wort are used to prepare teas, tablets, and capsules containing concentrated extracts. Liquid extracts and topical preparations are also used (R).

St. John’s wort contains hypericin and hyperforin, which both have health benefits (R).

However, St. John’s wort interacts with many medications, making the medications less effective (R).

Health Benefits of Saint John’s Wort

1) Saint John’s Wort Can Treat Depression

Depression may originate from a disruption of normal brain chemistry, specifically from a deficiency of neurotransmitters like acetylcholine, norepinephrine, dopamine, and serotonin. Antidepressant drugs typically raise the levels of those neurotransmitters (R).

Hypericin is the main antidepressant constituent of St. John’s wort because it stimulates capillary blood flow. Hypericin also helps regulate dopamine levels and increases the number of receptors in rat brains (R).

The administration of St. John’s wort is clearly helpful for treating mild to moderate depression. All the recent clinical trials suggest that St. John’s wort is more tolerable than synthetic antidepressants as it causes fewer side effects (R).

2) Saint John’s Wort Kills Bacteria and Viruses

Extracts of St. John’s wort have been used for thousands of years to treat cuts, abrasions, and other wounds. It is also useful in reducing inflammation, which is related to its antibacterial properties (R).

The main antibacterial component is  hyperforin. Hyperforin inhibits the growth of certain types of microorganisms (R).

Extracts of St. John’s wort are effective against various classes of viruses. Flavonoid and catechin-containing fractions of Saint John’s wort are active against influenza virus (R).

Hypericin inactivates enveloped viruses at different points in the viral life cycle and also inhibits the ability of viruses to fuse with cell membranes (R).

3) Saint John’s Wort May Have Anticancer Properties

In cells, hyperforin inhibits tumor cell growth (R).

Hypericin is also an anticancer agent, reportedly inhibiting the growth of cancer cells derived from a variety of tissues (R).

4) Saint John’s Wort Has Antioxidant and Neuroprotective Properties

Extracts of St. John’s wort decreased oxidative stress and consequently prevent brain damage, inflammation, and gastrointestinal problems. Thus, it may effectively treat oxidative stress-related brain disorders such as Parkinson’s and Alzheimer’s diseases (R).

The flavonols quercetin and kaempferol in St. John’s wort provide neuroprotective action by decreasing oxidation.  Thus, the plant serves as a brain-protecting agent against Parkinson’s disease in mice (R, R).

5) Saint John’s Wort Can Reduce Withdrawal Symptoms

St. John’s wort may act by activating the opioid receptors without causing withdrawal symptoms. It decreased the effects of opiate withdrawal in rats. The effectiveness of H.perforatum is equivalent to clonidine, an FDA-approved medication for treating withdrawal symptoms (R).

6) Saint John’s Wort May Treat Premenstrual Syndrome

Premenstrual syndrome (PMS) is a common condition. Serotonin might play a role in the production of PMS symptoms. Saint John’s wort influences the serotonergic system (R).

Daily treatment with Hypericum perforatum was more effective than placebo treatment for the most common physical and behavioural symptoms associated with PMS (R).

Buy St John’s Wort


  • The probable mechanism of the St. John’s wort action is the suspension of monoaminoxidase (MAO) as well as the suspended reuptake of serotonin (R).
  • The most common classes include naphthodianthrones, phloroglucinols, and flavonoids (such as phenylpropanoids, flavonol glycosides, and biflavones), as well as essential oils (R).
  • Additionally, there are two major active constituents: hypericin (a naph dianthrone) and hyperforin (a phloroglucinol) (R).
  • SJW extracts also inhibited the expression of proinflammatory genes like cyclooxygenase-2, interleukin 6, and inducible nitric oxide synthase (iNOS) (R).
  • Additionally, H. perforatum extracts decreased the activity of Janus kinase 2, leading to a series of reactions that inhibited the downregulation of signal transducer and transcription (STAT)-1 α DNA-binding. This also further disrupts gene transcription (R).
  • Pseudohypericin and hyperforin also inhibited production of the inflammatory agent prostaglandin E2 (PGE2) (R).


Many drugs interact badly with Saint John’s wort including SSRIs, statins, warfarins, and contraceptives. They can be a dangerous combination when taken together (R).

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  • Nejc

    What about discontinuation syndrome / withdrawal? I’m pretty sure stopping it cold turkey would have side effects.

  • mcfadden1968

    I disagree that
    – Hollie

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